Báo cáo "A study of waste water impacts of main factories on water quality of To Lich river, Ha Noi " doc

With the total amount waste water of factories Hanoi beer alcohol and beverage joint stock corporation HABECO, Trang An JSC and Thuong Dinh industrial park of 45,000 m3/day, these factor

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A study of waste water impacts of main factories on water

quality of To Lich river, Ha Noi

Tran Van Quy*, Tran Van Son

Faculty of Environmental Sciences, Hanoi University of Science, VNU, 334 Nguyen Trai, Hanoi, Vietnam

Received 9 September 2010; received in revised form 11 October 2010

Abstract Waste water from industrial sites amounts to one third of total waste water discharged

into To Lich river, and may have serious effects on the river water quality With the total amount waste water of factories (Hanoi beer alcohol and beverage joint stock corporation (HABECO), Trang An JSC and Thuong Dinh industrial park) of 45,000 m3/day, these factories accounts for more than a half of total industrial waste water released into To Lich river The analytic results of water samples taken from To Lich river show that the parameters of DO, COD, BOD5, TSS, NH4,

NO2- and coliform exceed the Vietnamese Standards (QCVN 08:2008, column B2) However, the concentrations of Fe and heavy metals (Zn, Cd, Cr, Cu, Mn), are lower than the Vietnamese Standards (QCVN 08:2008, column B2), except the concentration of ion Pb, especially in the area from Thuong Dinh Industrial Park to the last segment of the river The analytic results of waste water from the main factories (HABECO, Trang An JSC and Thuong Dinh industrial park, Hanoi Soap Joint Stock Company (HASO); Saovang Joint-stock Rubber Company (SRC); Tool No.1 Joint-stock Company (TJC)) show that, the parameters of TSS, BOD5, COD, total of nitrogen, total of phosphorus are higher than the Vietnamese standards for Industrial waste water QCVN 24:2009/BTNMT (column B) In particular, all waste water parameters of Trang An JSC are lower than the Vietnamese Standard for Industrial waste water QCVN 24:2009/BTNMT (column B), because the factory has an effective waste water treatment system The heavy metals parameters of waste water from all factories are lower than QCVN 24:2009/BTNMT Estimated loads of contaminants in waste water from the factories by load coefficient of IPC software show that without treatment, HABECO can release 1974 tons of BOD, 766 tons of TSS, 8.4 tons of phosphorus and 52.5 tons of nitrogen annually; Trang An JSC can release 64.8 tons of BOD, 48.6 tons of TSS, 0.6 ton of phosphorus, 1.6 tons of nitrogen and 25 tons of oil and grease; HASO releases 30 tons of BOD, 33 tons of TSS and 5 tons of oil and grease Thus, if the waste water is not treated, it can lead to a very seriously pollution for To Lich river

Keywords: To Lich river, sewage, IPC (Intergrated Pollution Control) software

1 Introduction ∗

Recently, there have recently been many

studies of status of water quality and solutions

of To Lich river However, there is not much

data surveys and impacts assessment of sources

_

∗

Corresponding author Tel.: 84-4-35580515

E-mail: tranvanquy@hus.edu.vn

affecting to water quality of the river, especially industrial waste water These sources account for more than one-third of total volume of waste water of To Lich river (about 70.000 – 75.000 m3/day) [1], but industrial waste water containing toxic compounds are cumulative of heavy metals or persistent organic biologocal compounds, research of waste water will positively contribute to the understanding of

pollution status and sources Since then, the

proposed measures can help to manage the

water quality of To Lich river

2 Materials and methods

To study the influence of waste water from

some main factories on water quality of To Lich

river, in this research findings previous studies

of river water quality were collected and

synthesized Then field surveying, site selecting

and sampling the river’s water and industrial

waste water from some main factories to

analyze and compare The water samples were

preserved and analyzed in the Laboratory of

Environmental Analysis, Faculty of

Environmental Sciences, Ha Noi University of

Sciences, VNU in accordance with the

Vietnamese standard methods Analytic

apparatus, including machine atomic absorption

spectrometry (AAS 6800, Japan), UV-VIS

Spectrometer, and a number of common

laboratory instruments and equipment are used

From the analytic results of waste water

components and data about flows from the

factories, the pollutants loads are calculated

(based on the parameters of software IPC -

Integrated Pollution Control) [3] and the impact

of this waste water on To Lich river water

quality is assessed

3 Results and discussion

3.1 Current Status of To Lich river water quality

According to the analytic results of river

water samples, To Lich river is generally very

polluted especially in the dry season In rainy

season, although pollutants water have been

diluted but it still does not ensure

environmental hygiene In particular, DO value

increases from upstream to downstream river; BOD5 value at the Hoang Quoc Viet Street and Cau Moi (Nga Tu So) are the lowest in the rainy season, respectively about 35 and 33mg/l, while that in Thuy Khe in the dry season is the highest (68mg/l), COD is 65–91mg/l (dry season) and about 50–74 mg/l (rainy season) Ratio between BOD/COD decreased gradually from upstream (0.78 mg/l) to the downstream side (0.65 mg/l)

TSS in river water is rather high from 69 to

135 mg/l Ammonium concentration in the river

is very high (approximately the lowest is 2 times and the highest is 8.3 times higher than with QCVN 08:2008, column B2) NO2 -concentration varies between 0.120 to 0.863 mg/l, higher than QCVN 08:2008, column B2 (0.05 mg/l) Coliform beyond permissible limits

in all samples (from 7 to 25 times) varies from 6.9*104 to 2.5*105 MPN/100ml

pH value and concentrations of Fe and heavy metals (Zn, Cd, Cr, Cu, Mn) in all positions lie within the limit permitted under QCVN 08:2008, column B2 However, Pb levels exceed permissible limits in some parts

of the river, which flows through the Thuong Dinh industrial zone and river sites are influenced by discharge of industrial activity (0.1295 mg/l at Nga Tu So) These results are relatively consistent with other studies’ findings [1, 2, 4]

3.2 The composition of waste water from factories into To Lich river

To assess the impact of waste water from

chosen factories on To Lich river water quality, sampling and components analysis in waste water from : HABECO (NM1); Trang An JSC (NM2); General discharge of waste water in Thuong Dinh Industrial Zone (NM3); HASO (NM4) SRC (NM5); TJC (NM6) are conducted The analytic results are given in Table 1

Table 1 Composition analytic results of waste water from some main factories

Samples of waste water from factories Parameters Unit

NM1 NM2 NM3 NM4 NM5 NM6 QCVN 24-2009, Column B

Temperature 0C 29,2 29,4 28,1 28,9 28,7 29,1 40

Fe mg/l 0,5689 0,5102 0,6421 0,6576 2,1512 1,8715 5

Cr+3 mg/l 0,0125 0,0312 0,0625 0,0571 0,0781 0,0421 1

Cu mg/l 0,0116 0,0183 0,0541 0,0149 0,0176 0,0132 2

Cd mg/l 0,0013 0,0017 0,0054 0,0065 0,0057 0,0036 0,01

Zn mg/l 0,0172 0,0234 0,0417 0,0167 0,0453 0,0716 3

Pb mg/l 0,4110 0,2391 0,4961 0,4902 0,5012 0,4892 0,5

Mn mg/l 0,0438 0,0517 0,1319 0,1376 0,1392 0,1903 1

(Source: Laboratory for Environmental Analysis–Faculty of Environmental Sciences–Ha Noi University of Sciences - VNU)

TSS, BOD5, COD of almost factories

exceed the legal standards TSS in waste water

of HABECO is the highest (200mg/l),

exceeding the correspondent standard QCVN

24:2009, column B by 2 times TSS in the

waste water of Trang An JSC and SRC are the

lowest, respectively at 85 and 81mg/l; BOD5 in

waste water of all factories varies from 45 to

250mg/l, and almost exceed the QCVN

24:2009, column B, except at Trang An JSC; COD in waste water from factories is quite high, three factories exceed QCVN 24:2009 column B, except Trang An JSC and SRC Total nitrogen in waste water of HABECO exceed the permitted limit, while other factories meet the standard Only parameters in Trang An JSC are standards Because the factory has built

a relatively efficient water treatment system

0 10 20 30 40

mg/l

NM1 NM2 NM3 NM4 NM5 NM6

factories

N-total in waste water from the factories

N-Total

Figure 1 Total nitrogen in waste water of factories

The concentrations of total phosphorus in

waste water from factories increase from

upstream to downstream of the river (ranging

from 5.1 to 5.9 mg/l) In particular, total phosphorus concentration in Thuong Dinh industrial zone is the highest (Figure 2)

4.5 4.8 5.1 5.4 5.7 6

mg/l

factories

P - Total in waste water from the factories

P - Total

Figure 2 Total phosphorus in waste water of factories

So, factories impact the water quality of the

To Lich River From the factory waste water

analysis it is found that, the main pollutants in

waste water in To Lich river Watershed

(HABECO, Trang An JSC) are organic matter,

nitrogen, TSS The concentrations of

non-biodegradable compounds, phosphorus, iron

and other heavy metals in waste water of the

factories in downstream of To Lich river

(Thuong Dinh industrial zone) are higher

Total waste water of the surveyed factories

(HABECO, Trang An JSC, Thuong Dinh

industrial zone), is about 45,000 m3/day,

accounting for more than a half of total

industrial waste water discharged into the river

Although, the waste water flow from factories

is not high compared with the main sources of

the river Because it includes many

non-biodegradable pollutants, it can cause severe

and lasting pollution for the To Lich river

3.3 The influence of pollutants loads in factory waste water on water quality of To Lich river

To assess the pollutants load in factory waste water to water quality of the river some parameters from the Integrated Pollution Control (IPC) software of the World Bank and the World Health Organization applied for developing countries were used [3]

Results show that, with current capacity the annual pollutants loads in factory waste water are as follows: HABECO discharges about

1974 tons of BOD, 766 tons of TSS, 8.4 tons of phosphorus and 52.5 tons of nitrogen; Trang An JSC - 64.8 tons of BOD, 48.6 tons of TSS, 0.6 tons of total phosphorus, 1.6 tons of nitrogen and 25 tons of oil and grease; HASO - 30 tons

of BOD, 33 tons of TSS and 5 tons of oil grease

Thus, the pollutants loads in waste water by three surveyed factories are quite high and the

highest is at HABECO If this waste water is

not treated before being discharged into the

river, it will greatly affect the water quality of

To Lich river

4 Conclusions

In most of the entire of To Lich river the

parameters of DO, COD, BOD5, TSS, NH4+,

NO2

-, coliform are higher than standards

However, the levels of Fe and heavy metals

such as Zn, Cd, Cr, Cu, Mn meet the standard,

only the concentration of Pb exceeds the

permitted standards, especially in Thuong Dinh

Industrial Zone

The quality of discharge water from

factories into rivers: the parameters such as

TSS, BOD5, COD, nitrogen, phosphorus in

waste water discharging into the To Lich river

from the factories (HABECO, Thuong Dinh

Industrial Zone, HASO, SRC, TJC) do not meet

the permitted standards Only Trang An JSC

has installed a water treatment system, so its

waste water discharge meets the standard The

concentrations of heavy metals in waste water

of the factories meet the standard

Calculations of pollutants loads in waste

water from some factories by IPC software

show that, if not treated, the annual pollutants

loads of HABECO are about 1974 tons of

BOD, 766 tons of TSS, 8.4 tons of phosphorus and 52.5 tons of nitrogen; Trang An JSC approximately 64.8 tons of BOD, 48.6 tons of TSS, 0.6 tons of phosphorus, 1.6 tons of nitrogen, 25 tons of oil and grease; HASO about 30 tons of BOD, 33 tons of TSS, 5 tons of oil and grease So, if not treated before being discharged into To Lich River, it will cause serious pollution to the river

References

[1] Project “Relevant Using of ToLich river’s water

and improve environmental sanitation condition

Environment and Sustainable Development Institute (VESDI).2008

[2] Nguyen Thi Bich Nguyet – Ha Noi University of

Science Research on effects of ToLich river’s

water to running water source and air environment in riverside small villages and proposes control methods 2008

[3] The software IPC – Intergrated Pollution

Control, World Bank (WB) and World Heath

Organization (WHO), 1995

[4] Nguyen Xuan Huan, Nguyen Quoc Viet, Hoang Thi Quynh Trang, Nguyen Tien Trung, Le Viet Cao– Ha Noi University of Science Study on the effect of domestic waste water on water quality of To Lich river and proposed solution

process, Soil Sciences Journal (2010) 124